Field of the Invention
The present invention relates to a technology for cleaning an opposing part located under a substrate in a substrate processing device which performs processing on the substrate.
Description of the Background Art
Conventionally, there is known a technology in which processing liquid is supplied to a lower surface of a substrate while the substrate is being rotated. In such a type of device, part of the processing liquid supplied to the lower surface of the substrate is scattered and is stuck to an opposing part having an upper surface opposed to the lower surface of the substrate. If the processing liquid stuck to the upper surface of the opposing part is left as is, the processing liquid can be solidified to be a particle contaminating the substrate; therefore, cleaning processing is performed on the upper surface of the opposing part at appropriate timing.
For example, in the devices described in Japanese Patent Application Laid-Open No. 2014-179490 and Japanese Patent Application Laid-Open No. 2015-188031, the upper surface of the opposing part is configured to be inclined diagonally downward from the central part toward the outer circumferential part. With this arrangement, cleaning liquid is supplied to the central part of the upper surface of the opposing part, and the cleaning liquid flows to the outer circumferential part along the inclination of the upper surface, whereby the cleaning liquid washes away the processing liquid stuck to the upper surface of the opposing part.
However, even if cleaning liquid is supplied to the central part of the upper surface of the opposing part, the processing liquid resides at the upper surface of the opposing part in some cases, and there is a room for improvement in the technology of cleaning the opposing part.